In general, the transportation of portage in a factory or a warehouse is achieved by a crane or transport vehicle. However, the transportation of portage using the crane has the problems in that a range within which the portage can be transported and the weight of the portage are restricted. In the transportation of portage using the transport vehicle, the range within which the portage can be transported and the limitation for weight of the portage are broader as compared with the transportation of portage using the crane, but the transportation of portage using the transport vehicle is disadvantageous in that as a vertical load of the portage is increased, the friction force is increased to thereby require large power for transporting the portage and tires and a road may be damaged due to the load concentrated to the tires of the transport vehicle.
Accordingly, in recent, a method in which air foil is formed on the ground or rails using compressed air to transport a portage has been proposed and utilized. However, such a method has a problem in that an expected place to which the portage is transported should be paved with special paint for making the ground flat or additional rails should be provided. In addition, when the ground or the rails are not flat, air locally leaks thereby not obtaining a levitation effect. Accordingly, there is a problem in that the transporting means and the portage fall to be damaged.